The time-varying influence of a sailor’s position is typically neglected in dinghy velocity prediction programs (VPPs). When applied to the assessment of dinghy race performance, the position and motions of the crew become significant but are practically hard to measure as they interact with the motions of the sailboat. As an initial stage in developing a time accurate dinghy VPP this work develops an on-water system capably of measuring the applied hiking moment due to the sailor’s pose and compares this with the resultant dinghy motion. The sailor’s kinematics are captured using a network of inertial motion sensors (IMS) synchronised to a video camera and dinghy motion sensor. The hiking moment is analysed using a ‘stick man’ body representation with the mass and inertial terms associated with the main body segments appropriately scaled for the representative sailor. The accuracy of the pose captured is validated using laboratory based pose measurements. The completed work will provide a platform to model how sailor generated forces interact with the sailboat to affect boat speed. This will be used alongside realistic modelling of the wind and wave loadings to extend an existing time-domain dynamic velocity prediction program (DVPP). The results are demonstrated using a single handed Laser and demonstrate an acceptable level of accuracy.